Comparing Discrete Wavelet Transform (DWT) with Discrete Fourier Transform (DFT) implemented for digital relays

This paper critically assesses the implementation of algorithms for Phasor Estimation using the Discrete Wavelet Transform (DWT) in a digital relay. The performance of different wavelets using varying levels of recursion in the implementation are presented. It finds that the computational power required to implement Phasor Estimation using the Discrete Wavelet Transform is similar to using the Discrete Fourier Transform (implemented using the FFT). It found that Phasor Estimation using the Discrete Wavelet Transform offers no advantage when detecting the fundamental phasor in a signal with harmonic content. Changing the wavelet used or the level of recursion had little effect on the accuracy.